1. The one-time pass rate of the package is not high, the contrast is low, and the maintenance cost is high;
2. The uniformity of color rendering is far inferior to the display screen after the SMD device with light splitting and color separation.
3. The existing COB package still uses the formal chip, which requires die bonding and wire bonding technology. Therefore, there are more problems in the wire bonding process and the process difficulty is inversely proportional to the pad area.
4. Manufacturing cost: Due to the high defect rate, the manufacturing cost far exceeds the small pitch of SMD.
Based on the above reasons, although the current COB technology has achieved certain breakthroughs in the display field, it does not mean that SMD technology has completely withdrawn and declined. In the field of dot pitches above 1.0mm, SMD packaging technology relies on its mature and stable product performance. Extensive market practice and perfect installation and maintenance guarantee system are still the leading role, and they are also the most suitable selection direction for users and the market.
